HARRISBURG - A House panel tonight approved changes to Philadelphia's budget-relief package that would strip out most of the provisions organized labor vehemently opposed in recent days.

The full House is expected to vote on the plan, which would still allow Philadelphia to temporarily raise the sales tax by a penny on the dollar and to defer payments to the city pension fund as Mayor Nutter first sought, as early as tomorrow.

But even if passed, its future in the GOP-controlled Senate remains in doubt.

The House Rules Committee voted unanimously for an amended version of the relief package, capping a daylong drama in the Capitol in which officials, until shortly before the vote, closely guarded details of the amendment as they tried to reach a compromise with the Senate.

Information was sparse even for the mayor of the state's largest city, who spent the day in Harrisburg lobbying for the relief package.

In an interview at 6 p.m., two hours before the vote, Nutter said he hadn't seen a final version of the amendment that was the last best hope for the city to avoid thousands of layoffs.

"We've done every possible thing that we could do to prevent this, yet we are caught up in a political maelstrom where action gets taken but there is seemingly never a resolution," said Nutter, who was clearly frustrated with the slow pace of Harrisburg.

Wrangling over the city's pension issue has dominated backroom discourse in Harrisburg in recent days even as the state was grappling to reach an agreement on its own budget.

And time is running out for the city.

At noon tomorrow, the city's financial watchdog, the Pennsylvania Intergovernmental Cooperation Authority (PICA), is scheduled to vote to accept, or reject, Nutter's "doomsday" budget, known as Plan C.

It calls for 3,000 city layoffs, eliminates funding for Philadelphia's court system, and closes every city library and recreation center, among other budget-cutting steps.

It was unclear today how board members would vote.

But PICA Chairman James Eisenhower said, "There certainly is a concern about a budget that does not fund the court system, and as a former prosecutor, I certainly have that concern.

"I don't think that is tenable."

If the board rejects the plan, it has the authority to withhold the PICA portion of the city wage tax - about $30 million a month - and to file a court action to compel the city to file a balanced budget.

With all the uncertainty, the city moved ahead yesterday preparing to implement Plan C.

The House originally passed the relief package Aug. 5.

It allowed the city to defer pension contributions and impose a 1 percentage point increase in the sales tax until 2014 to help cover budget shortfalls.

But three weeks later, the Senate amended the bill to include far-reaching provisions dealing with municipal pensions across the state. Among other things, that version would allow the state to take over weaker-performing pension plans and freeze benefits for some plan members.

Those changes, which balloon the bill to 97 pages, have drawn the intense backlash of organized labor statewide, most notably from police and firefighter unions. They argued that it would wrongly restrict their rights at collective bargaining during contract talks.

The House amendment would strip out many of the changes sought by the GOP-controlled senate.

Sen. Pat Browne (R., Lehigh), chairman of the Finance Committee and the point man on the pension changes, said the amendment would "remove the foundation of what we were trying to do" - stabilize weaker municipal pensions across the state.

And he predicted that if it passes the House, the measure "would not garner the necessary votes" in the Senate.

Contact staff writer Mario F. Cattabiani at 717-787-5990 or mcattabiani@phillynews.com.